Like much of the rest of Southeast Asia, Thailand offers an awful lot to travelers. Beautiful beaches and landscapes, great weather, fantastic food, and low prices make it an appealing destination, and many millions of visitors flock to the country every year.
For those looking to stay connected in the Land of Smiles, buying a prepaid SIM card as a tourist is a fairly straightforward and inexpensive process. Data allowances are typically quite generous, and you’ll get decent speeds and good coverage almost anywhere you’re likely to be.
We’ve spent years traveling through the country, from busy cities and towns to quiet islands and isolated rural areas. Having tried all the major cell companies, we’ve found the best Thai SIM card for most visitors, whether you’re on vacation for a few days or plan to stay for weeks or months at a time.
Here’s everything you need to know.
There are three cell networks in Thailand, operated by dtac, AIS, and TrueMove. While you can also buy SIM cards and service from resellers, there’s little point in doing so for most tourists and other short-term visitors.
AIS has the best coverage and largest market share, plus a large network of Wi-Fi hotspots you can access as part of the more expensive packages. It seems like you’re rarely far from one of these hotspots in any good-sized city or town, and they don’t count towards your mobile data allowance.
Prices are broadly similar to the competition, so for the majority of visitors to Thailand, AIS SIM cards are the best option. 3G/HSPA+ is available on the 900 and 2100Mhz bands, while 4G/LTE is provided on 1800 and 2100Mhz (LTE bands 1 and 3).
5G is being rolled out, although it’s still confined to major cities at this stage. Most international visitors are unlikely to have phones that support the right frequencies for 5G, and given that 4G/LTE is cheaper, much more widespread, and often still pretty fast, it’s not something to worry too much about at this stage.
I’ve also used TrueMove and dtac’s Happy prepaid services, and both provided good coverage and speeds in towns and cities. They did have noticeable service gaps in rural areas and on less-populated islands, however.
All providers offer LTE service in 80-90% of the country, including all major cities and towns.
How to Buy a Prepaid SIM Card in Thailand
Like many other things in Thailand, buying a SIM card is quite simple, especially if you fly into either of Bangkok’s airports. At both Suvarnabhumi and Don Mueang, all three cell companies have booths beside each other in the arrival hall.
The booths at Suvarnabhumi are often busy, with long lines for all providers. Staff are efficient and the lines move fairly quickly, but if you’re tired and grumpy after a long flight, it’s not the most enjoyable experience.
dtac (Happy) has a self-service machine right beside its booth in the main arrival area, which takes cards and Thai baht notes. Customers generally seem to ignore it despite the long line for counter service, so it’s a good option if you didn’t need assistance.
It’s possible to buy SIMs at other international airports in Thailand as well, including Phuket and Chiang Mai. Many of the airport SIM card stalls shut down during the pandemic, but with things opening up, most of them have returned as of mid-2022.
If you don’t mind spending a bit more to be connected quickly and easily when you first arrive, feel free to pick up one of these tourist SIM card packages. If saving money is more of a priority, you’ll get better deals at convenience stores and official retail shops elsewhere.
Elsewhere, in this case, doesn’t necessarily even mean leaving the airport. If you’ve flown into Suvarnabhumi and are taking the train into Bangkok, pop into the 7-11 near the Airport Rail Link entrance in the basement of airport before you leave. There, you’ll find the usual range of SIM card packages, with standard pricing or very close to it.
Thailand bought in stricter requirements for buying SIMs a few years ago, which means the days of just handing over cash at the corner store are gone. Foreigners now need to provide their passport and potentially have their photo taken as part of the registration process.
I experienced this first hand on previous trips to Bangkok, both at a 7-11 and an official carrier store in a shopping mall. In both cases, the staff member took a copy of my passport and snapped a photo of me on a phone or tablet app.
I’m not a fan of onerous identification requirements like these. Unless you’re buying from a street vendor and are happy with a used SIM that could be shut off at any time, however, you’re pretty much stuck with it.
On the upside, the rest of the process was relatively painless. At the store, I took a number for an English-speaking sales rep, picked a call/text/data package from a printed brochure at the counter, and handed over the money.
The rep did the rest, including activating the SIM, loading my credit onto it, and selecting the right package. It took about ten minutes in total, and the SIM worked immediately.
At the 7-11, I asked for a basic SIM card, then picked a package from a list on the cashier’s screen. After paying for the card and a top-up voucher to cover the total amount, I installed the SIM and added the credit using the instructions on the voucher.
Finally, the cashier gave me the right text code to enter for the package I was after, which activated immediately. Again, the process took about ten minutes.
Prepaid SIM Costs
Most of the tourist SIM cards sold at airports in Thailand offer “unlimited” data packages. With them, you get a certain amount of high-speed data, and greatly-reduced speeds after that. A small amount of call credit may or may not be included as well.
In March 2022, the plans at the Happy stand at Suvarnabhumi airport baggage reclaim were as below.
In summary, you either get truly unlimited data capped to a particular speed, or a fairly large amount of data at full speed followed by unlimited amounts of slower data, for a certain length of time. They all come with some sort of domestic call allowance as well, either a certain amount of credit or a number of minutes.
Both AIS and TrueMove had broadly similar pricing, albeit with some variation in data allowances and validity periods. None are great value compared to purchasing outside the airport, but they’re still relatively inexpensive by global standards.
If you’re happy to wait, buy your SIM card from a convenience store or official outlet elsewhere in Thailand instead. There, you’ll have access to the full range of call, text, and data packages. They are many and varied, with validity ranging from a day to a month or more.
Note that if you’re planning to buy from a convenience store, not all chains sell all SIM cards. 7-11 doesn’t sell AIS SIMs, for example, and a Tesco Lotus store I walked into near Don Mueang didn’t sell SIM cards at all.
I usually buy from convenience stores, but have gone through the effort of seeking out at an AIS store in a mall in Bangkok in the past. Unless you happen to be staying close to one, there’s no particular need to do this: it’s likely to take longer, and any financial saving will be minimal.
In the interests of research on my most recent trip, I decided to buy a Happy SIM at the airport rather than going for my usual AIS option in town. Since I’d be in Thailand for a couple of months, I went for the 899 baht (~$28) package that gave 60GB of high-speed data per month, valid for 90 days. It’s more than I’ll ever use.
You can buy top-ups pretty much anywhere in Thailand, including many convenience stores, AIS retail locations, and several other places. Just keep an eye out for the AIS/1-2-Call logo. It’s also possible to top up online with a credit/debit card on the AIS website.
No matter how you top up, you may then need to purchase or renew the actual package you want to use. Be sure to do this, as the default call, text, and data rates aren’t particularly cheap.
Calling *777# from your phone should give an interactive menu for choosing your package — take a look on the AIS site for more details. To switch your AIS SIM from Thai to English, enter *700*9*7*2# and wait a minute or two for the confirmation text.
Coverage and Data Speeds
AIS coverage is good almost anywhere you’re likely to go as a tourist, and much of the rest of the country as well.
I’ve had full signal most of the time in Bangkok, Chiang Mai, Phuket, and other provincial capitals, as well as on bus and scooter trips in the countryside and on several islands. I even had service for a while after crossing the border into Cambodia, at least until I got outside the range of the last Thai cell tower.
It’s also worth mentioning the exceptional speed of the AIS SUPER WI-FI network. I regularly saw over 150Mbps download speeds when connected to it, and since it doesn’t count towards your cellular data allowance, it’s well worth using this network if your SIM package includes access to it.
Data speeds are reasonable, but definitely vary depending on where you are, and how busy the cell tower is that you’re using. I had much faster LTE speeds in Chiang Mai than Bangkok, for instance.
As mentioned earlier, TrueMove and dtac/Happy coverage and speeds are good in populated areas but can drop off in more isolated spots.
Traveling through the Trang island group with a TrueMove SIM, for instance, LTE availability was hit or miss, although I usually (but not always) had 3G/HSPA+ service with usable but not fast speeds. 4G/LTE speeds in Phuket, however, were very quick.
On my most recent trip with a Happy SIM, LTE download speeds were pretty good in Bangkok and Hua Hin, only occasionally slowing down to any noticeable degree. Upload speeds weren’t as impressive, but they were still enough for video calls and anything else I wanted to do.
Downloads were even faster in Krabi and Ao Nang, and remained surprisingly quick on popular nearby islands like Koh Phi Phi and Koh Lanta. Speeds were also good on Koh Samui, Koh Phangan, and Koh Tao, with reliable service everywhere except a few of the more isolated spots in the center of the islands.
Check out our guides to buying SIM cards in many other countries here.